1. Field of Invention
The present invention relates to a power module and a power conversion apparatus.
2. Related Art
Recently, the power technology has been developed and applied to various fields such as electricity power, chemical engineering, and communication. Regarding to the electricity power field, there are mainly a single-phase power system and a three-phase power system, which is applied to most industries.
FIG. 1A is a schematic diagram showing a conventional three-phase power conversion apparatus disclosed in U.S. Pat. No. 6,301,130. As shown in FIG. 1A, the power conversion apparatus 1 is cooperated with a load M, and includes a primary circuit 11 and a plurality of secondary circuits 12. The primary circuit 11 includes a primary winding W1. The secondary circuits 12 are coupled with the primary circuit 11, respectively, and each secondary circuit 12 includes a secondary winding W2 and a power module 121.
FIG. 1B is a schematic diagram showing a conventional power module disclosed in U.S. Pat. No. 6,301,130. As shown in FIG. 1B, the power module 121 includes a rectifying unit Rec composed of several active switching elements SW. Although the conventional power module 121 can modulate the current to sine wave or substantially sine wave without configuring additional auxiliary circuit for phase shift, the circuit structure thereof is still very complex since the power module 121 is configured with many switching elements SW. Accordingly, the reliabilities of the power module 121 and the power conversion apparatus 1 are threatened.
Therefore, it is an important subject of the present invention to provide a power module and a power conversion apparatus that have a simplified circuit design as well as increased reliabilities.